As of this writing, there are currently 1,397 potentially
hazardous asteroids. These objects cross Earth's orbit or pass by Earth
periodically. Any given object is on a very different orbit from the others.

Here is a thought exercise to visualize the issue: Nearly flatten
a ball of yarn then press a marble into the center. The marble represents
Earth. Each of the strands of yarn represents the orbital path of thousands
of asteroids of all sizes.

There are 10,000+ smaller objects and countless others which remain
unknown. Yet none of these asteroids hit Earth, except an occasional small
object which grazes our atmosphere and usually burns up before impact. Over
time this fact defies the odds of not hitting Earth.

It is not just the size of the Earth which makes a great target. Our
Moon's average distance to Earth is 238,857 miles. It only stays at that
distance by staying in motion at 2,280.68 miles per hour. If it was stationary
it would have crashed into Earth eons ago. This shows us that Earth's gravity
field extends much further out into space than the distance of the Earth
to the Moon.

But there is more to this story about missing impacts than just the
size of the Earth being a big target. Earth is also a roving vacuum cleaner
in our part of the solar system. A slow moving asteroid would be attracted
toward Earth at more than twice the distance of the Earth to the Moon. Earth's
gravity field extends out more than 500,000 miles into space in every direction
from Earth. This conservatively equals a total spherical gravity net diameter
of at least 1,000,000 miles. In reality, there is no distance where Earth's
gravity is suddenly zero.

There is a distance at which point gravitational pull would become
irrelevant to attracting asteroids towards Earth. This distance is relative
to mass and velocity of any asteroid, and determines whether or not Earth's
gravity will affect it. Gravitational force is the warping of space-time.
It is a logarithmic function, not linear. Logarithmic means that the further
away you are from Earth, the less gravity reduces for each mile. Using our
Moon as an example 238,857 miles away, a vacuum cleaner effect for Earth
1,000,000 miles in diameter is a very conservative number. Although gravity
effects are weaker one million miles away, there is still all the time in
the universe to move any asteroid closer and closer to Earth.

In February 2013, asteroid 2012 DA14 missed Earth by just 17,200 miles.
This is about 5,300 miles closer than geostationary orbiting communications
and television satellites. Yet the object still did not hit Earth or one
of the satellites.

Further, it is known that orbits of most asteroids have the same or
similar orbital plane as Earth has around the Sun. This greatly increases
the odds of Earth being hit.

Gravity should cause many of these objects to hit Earth at least periodically.
But these impacts simply have not happened, and it defies the odds. Perhaps
the dinosaur extinction event was the last big impact allowed millions of
years ago. Or, perhaps it was forced to happen.

Clearly an intelligence is out there preventing asteroid impacts of
any significant size. We have known for a very long time we are not alone
in this universe. Those that visit Earth and use its resources (including
DNA from people) have a deep interest in protecting Earth from asteroid
impacts. Yet science remains completely silent about missing asteroid impacts.
For the science world to admit we are being protected requires admitting
there is alien life, which isn't going to happen anytime soon.